Manually controllable medical aid oscillator instrument

ABSTRACT

A medical aid instrument producing an audible rhythmical cadence for initiating and sustaining a walking pattern comprising a relaxation oscillator which produces beats in the range of 30 to 120 per minute and has a manual on-off switch under control of the patient. An embodiment of the invention includes a relaxation oscillator, a phase shift oscillator controlled by said relaxation oscillator, and an audio amplifier following the phase shift oscillator. The output of the audio amplifier may be connected to an ear plug or to an electrode assembly adapted to be felt by the patient.

United States Patent [72] inventor Robert L. Konvalin Hicksville, N.Y. [21] Appl. No. 530,542 [22] Filed Feb. 28, 1966 [45] Patented Mar.l6, 1971 [73] Assignee Cargille Scientific, Inc.

Cedar Grove, NJ.

541 MANUALLY CONTRCL LABLE MEDICAL AID OSCILLATOR INSTRUMENT 1 Claim, 4 Drawing Figs.

[52] [1.8. CI 128/1, 128/422 [51] Int. Cl. A6ln l/36 [50] Fieldot'Seai-ch 128/419 (P Digest), 1, 2, 421-424; 84/484; 331/135, 1 l 1 [56] References Cited UNITED STATES PATENTS 3,108,597 10/1963 Moss et a1 128/422 3,164,783 l/l965 Houpt 331/135X 3,274,995 9/1966 Sturm..... 128/2 3,364,929 l/l968 Ide et al. 128/419X 3,057,356 10/1962 Greatbatch.... 128/422 3,311,111 3/1967 Bowers 128/422 FOREIGN PATENTS 619,129 3/1961 Italy 128/l.03

Primary Examiner-William E. Kamm Attorney-Charles H. Brown Patented March 16, 1971 2 Sheets-Sheet 2.

Kim/r4770 we I N YEN TOR Kai/m4 /4/ MANUALLY CGNTROLLLE WDICAL A OSCILLATGR INSTRUMENT This invention concerns an instrument for assisting a victim suffering from Parkinsons syndrome, and particularly an instrument for producing an audible rhythmical cadence for the purpose of initiating and sustaining a good walking pattern.

The instrument of the invention is a small, compact, lightweight, portable pacing device provided with an earplug and which can be carried inconspicuously by the patient. When the patient feels that he is freezing (not able to maintain his walking), he can switch "on the instrument and receive a predetermined audio beat in his car, via the earplug, and thus help continue his gait pattern. Two theories have been advanced for the assistance provided by the invention to persons suffering from Parkinsons syndrome: (1) that upon the receipt of an audible beat, the vestibular system (hearing system) bypasses the short circuiting in that part of the brain which controls the semiautomatic reflex (semiautomatic voluntary movement), and (2) the effect is a conditioned reflex (conditioned response through repetitive teaching) which acts much the same way as when a soldier is ordered to attention. He responds immediately with little or no conscious thought initiating his act. It should be understood, of course, that the invention is independent of the correctness of any theory advanced for the results obtained. The invention is also useful in achieving an even (regular) walking cadence in patients learning to walk with a prosthesis (artificial leg) or patients who stiffer from uneven gait patterns due to neurological disorders.

Advantages of the present invention are fourfold: (1) It aids the patient to initiate and maintain walking, and is useful in training to achieve an even gait pattern; (2) it is manually operated by the patient who carries this extremely compact and lightweight instrument-on his person; (3) it eliminates the necessity of having a second person present to count cadence; and (4) it is portable and inconspicuous.

The medical aid instrument of the invention is a novel transistorized compact, lightweight pacer which is carried on the person and provides a well-regulated steady beat easily sensed by the patient. The beat may come in the form of short duration clicks, or preferably in the form of spaced, pulsed low-frequency tones from an audio'oscillator. Musical tones are believed to be more acceptable to victims of Parkinsons disease than ticks. The use of an earphone (earplug) assures direct impact on the hearing system, and is desirable from a cosmetic standpoint.

A more detailed description of the invention follows in conjunction with a drawing, wherein:

FIG. la illustrates the novel transistorized pacer of the invention;

FIG. lb is a voltage waveform curve given to explain the operation of the circuit of FIG. la;

FIG. 2 illustrates another embodiment of the invention utilizing thetransistorized audio frequency pacer of FIG. I modified to provide pulsed low-frequency tones periodically repeated at a selectable audible rate; 1

FIG. 3 illustrates a modification of a system of FIG. 2.

Throughout the FIGS. of the drawing, the same parts are designated by the same reference numerals.

The circuit of FIG. 1a is a relaxation oscillator comprising an NPN transistor 6 and a INP transistor 7 both connected in the common emitter configuration. The base of the transistor 7 is connected to the collector electrode of transistor 6. There are also provided a potentiometer 3, a fixed resistor 4, a switch 2, a small battery 1 and an earplug 8. One terminal of the battery and the tap on the potentiometer are connected to a point of reference potential, such as ground. The earplug 8 is designed for insertion into the ear of the patient for reproducing into the ear of the patient the regulated beat produced by the relaxation oscillator.

As is known, for an NPN transistor to conduct, both the base and'the collector electrodes must be positive relative to the emitter. To cease conduction, the base of the NPN transistor must be negative relative to the emitter, though the collector can still be positive. For a PNP transistor to conduct, both the base and the collector must be negative relative to the emitter. To cease conduction, the base of the PNP transistor must be positive relative to the emitter, while the collector can still be negative.

The operation of the relaxation oscillator will now be given: Let it be assumed that transistor 6 is off (no current flowing therein). The closure of switch 2 will raise the voltage on the base of transistor 6 to a positive value. The closure of switch 2 causes a flow of current from battery 1 through potentiometer; 3 and resistor 4 into capacitor 5 and through earplug 8 to the negative terrninal of battery ll, thereby charging capacitor 5. Transistor 6 will start to conduct as a result of which the voltage on the base of transistor 7 becomes negative and causes transistor 7 to conduct. The system soon saturates; that is, transistor 7, when it conducts, can be considered as a closed switch through which capacitor 5 discharges and another cycle of operation begins. The waveform at point A in the relaxation oscillator of FIG. la is as shown in FIG. lb. The waveform shape depends upon the time constant of the circuit. With each cycle an audible click is heard in the earplug 8. The approximate rate of the clicks is determined by the RC product of the sum of the resistances in potentiometer 3 and resistor 4 in ohms and the capacitance of the capacitor 5 in microfarads, or (4 3) X 5. By adjusting the potentiometer 3, various valves of R may be selected to provide an adjustable click rate. Resistor 4 determines the upper limit of the click rate range. Thus, suitable values may be chosen to provide click rates in the preferred audible range of 30 to c.p.m. (cycles per minute); viz, rto 2 clicks per second, for use as a medical aid instrument to assist a patient suffering from Parkinsons syndrome.

The system of FIG. 2 provides for a selection of three pulsed audio tones responsive at the click rate of the relaxation oscillator. The relaxation oscillator circuit of FIG. 2 is the same as that of FIG. la except for the use of a relay 10 in the output of the PNP transistor 7 to replace the earplug 8 which appears in another part of the system. The system of FIG. 2 is divided into three sections identified as (1) an audio relaxation oscillator or pulsing circuit using the two transistor arrangement 6 and 7 of FIG. la followed by (2) an audio phase shift oscillator. using a PNP transistor 9 and (3) an audio amplifier using a FNP transistor 20.

The relaxation oscillator or pulsing circuit of FIG. 2 has hereinabove been described in connection with FIG. 10. Each cycle of operation thereof results in the closure of a relay 10 the contacts 25 of .which actuate the audio oscillator. The audio oscillator uses the twin T network 11 to provide the desired phase shift from the collector electrode of PNP transistor 9 to its base electrode. The twin T network provides selectable phase shifts and hence selectable frequencies of operation through the use of resistors 12, 13 and Hand selector switch 15. The selection of the different resistors l2, l3 and M by switch 15 will give different respective tonal outputs for amplification by the audio amplifier 20. The movement of selector switch 15 to the position B serves to disable the audio oscillator by grounding the collector electrode of transistor The load resistance for this audio oscillator is the potentiometer 16 which also serves as a volume control for the audio amplifier and earplug 8. This type of audio oscillator provides good stability and a sinusoidal output.

In the operation of the system of FIG. 2, the relay l0 responds to the pulse rate of the relaxation oscillator as determined by the adjustment of potentiometer 3, and the contacts 25 open and close accordingly. As the contacts 25 are in series between battery 1 and the audio oscillator-amplifier circuits, these circuits will be pulsed on and off at the pulse rate of the relaxation oscillator. Therefore, in the first three positions of the selector switch 15 which selectively insert one of the three resistors 12, T3 or 14 into the audio oscillator circuit, audio tones of different sinusoidal frequencies will be interrupted at the relaxation oscillator rate. In the fourth position of the selector switch 15, position 13, the audio oscillator is disabled and only clicks will be amplified by the audio amplifier and heard in the earplug. Hence, the patient can utilize either tones or clicks depending upon the position of the selector switch 15.

The audio level or intensity is a function of the position of the tap on potentiometer 16. This tap is coupled through a coupling capacitor 17 to the base of audio amplifier transistor 20. Resistors 18 and 19 in the audio amplifier circuit are biasing resistors. Resistor 22 determines the emitter bias for transistor 20, and capacitor 21 provides adequate bypassing of resistor 22 for the frequencies used. The earplug 8 provides the load impedance for the collector electrode of transistor 20.

In embodiments of FIGS. 1a and 2 successfully tried out in practice the components used had the values listed below:

FIG. 1a

1-1.5 Volts 2-Toggle Switch 3-200,000 Ohms 4-91,000 Ohms 5-10 mfd, 12 Volts 8-l-learing Air Earphone FIG. 2

l-9 Volts Z-Toggle Switch 3-200,000 Ohms 4-9 1 ,000 Ohms 5-10 mfd., Volts 8-Hearing Aid Earphone lO-Reed Relay ll-Rl R2-l50,000 Ohms 12-5600 Ohms 13-2400 Ohms 14-1 100 Ohms 15-4 Position Rotary 16-2500 Ohm Potentiometer 17-15 mfd. 12 Volt 18-4700 Ohms 19-33,000 Ohms 20--2N323 21-10 mfd., 12 Volts 22-470 Ohms pulsed tonal frequencies produced by the audio oscillator in the different selectable positions of the selector switch 15 for the values of resistors 12, 13 and 14 given above were 1500 cycles, 3000 cycles and 6000 cycles, respectively.

H6. 3 shows an alternative to the use of an earplug 8 in the system of FIG. 2. In FIG. 3 a step up transformer 26 is shown connected to the audio amplifier. The secondary winding S of the transformer is coupled via connections 23 to a pair of electrodes 24, suitably arranged to be felt by the patient by making use of the sense of touch. If a suitable switch, not shown, is employed in the output circuit of the audio amplifier, and the step-up transformer arrangement is also used, then, at the option of the user, the patient may either hear the beats of tonal frequencies over the earplug or feel them on a suitable part of the body, such as the wrist. The system can be miniaturized by the use of integrated circuits, so that the entire system can be made to occupy the space of an earplug, or made so compact as to be inconspicuously concealed behind the ear.

If desired, the audio amplifier of FIG. 2 may be eliminated, in which case one terminal of the earplug will be directly connected to the collector electrode of the twin T network phase shift audio oscillator while the other terminal of the earplug will be directly connected to the upper contact of the relay 10.

Further more the relaxation oscillator, when used by itself may be modified to produce audio tones rich 1n harmonics or overtones interrupted at a periodic selected rate in the range of 30 to pulses per minute.

I claim:

1. A medical aid instrument in the form of an electronic pacer easily carried externally on a patient for producing an audible rhythmical cadence for initiating and sustaining a walking pattern by providing a steady beat to be sensed by said patient comprising a relaxation oscillator producing periodic beats in the range substantially of 30 to 120 beats per minute, a manual switch under control of said patient for turning said relaxation oscillator on and off, and a transducer coupled to said relaxation oscillator for attachment to said patient, said relaxation oscillator having a relay in its output which is energized at the beat rate of said relaxation oscillator, said relay having a pair of contacts, a battery connected to said switch and to one of said contacts, a phase shift audio oscillator coupled between the other contact of said relay, said battery and said transducer, said audio oscillator having a twin T network, a plurality of differently valued resistors associated with said twin T network for providing selectable phase shift and hence selectable frequencies, and a selector switch for effectively selecting and connecting any one of said resistors into said audio oscillator, whereby said audio oscillator produces spaced pulses of selectable audio frequencies, an audio amplifier in the output of said audio oscillator and located between said audio oscillator and said transducer, said selector switch being provided with a movable arm connected to ground and with a contact connected to the output of said audio oscillator, whereby movement of said arm to engage said last contact disables said audio oscillator. 

1. A medical aid instrument in the form of an electronic pacer easily carried externally on a patient for producing an audible rhythmical cadence for initiating and sustaining a walking pattern by providing a steady beat to be sensed by said patient comprising a relaxation oscillator producing periodic beats in the range substantially of 30 to 120 beats per minute, a manual switch under control of said patient for turning said relaxation oscillator on and off, and a transducer coupled to said relaxation oscillator for attachment to said patient, said relaxation oscillator having a relay in its output which is energized at the beat rate of said relaxation oscillator, said relay having a pair of contacts, a battery connected to said switch and to one of said contacts, a phase shift audio oscillator coupled between the other contact of said relay, said battery and said transducer, said audio oscillator having a twin T network, a plurality of differently valued resistors associated with said twin T network for providing selectable phase shift and hence selectable frequencies, and a selector switch for effectively selecting and connecting any one of said resistors into said audio oscillator, whereby said audio oscillator produces spaced pulses of selectable audio frequencies, an audio amplifier in the output of said audio oscillator and located between said audio oscillator and said transducer, said selector switch being provided with a movable arm connected to ground and with a contact connected to the output of said audio oscillator, whereby movement of said arm to engage said last contact disables said audio oscillator. 